In order for the body to take in oxygen and give off carbon dioxide, two components of the respiratory bronchial system must function—the lungs as a gas-exchanging organ and the respiratory pump as a ventilation organ that transports air into the lungs and back out again. The breathing center in the brain, central and peripheral nerves, the osseous thorax and the breathing musculature as well as free, stable respiratory paths are necessary for a correct functioning of the respiratory pump.
In certain diseases there is a constant overload on or exhaustion of the respiratory pump. A typical syndrome is pulmonary emphysema with flat-standing diaphragms. Flat-standing diaphragms do not have the ability to contract. In the case of pulmonary emphysema, respiratory paths are usually extremely slack and tend to collapse. As a consequence of the flattened, over-extended diaphragms, the patient cannot inhale deeply enough. In addition, the patient cannot exhale sufficiently due to collapsing respiratory paths. This results in an insufficient respiration with an undersupply of oxygen and a rise of carbon dioxide in the blood, i.e. a ventilatory insufficiency.
The treatment for inhalation difficulty often involves a breathing device. A home ventilator is an artificial respirator for supporting or completely relieving the respiratory pump. Artificial respiration can be applied non-invasively via a nose or mouth mask that the patient can put on and take off as needed. However, the nose or mouth mask prevents the patient from breathing and speaking freely, and is very invasive.
Another treatment option is invasive ventilation. Invasive ventilation is usually applied via a cuffed endotracheal tube that is passed through the mouth and the larynx and into the windpipe, or is applied via a tracheostomy. The tracheostomy involves an opening placed in the trachea by an operation. A catheter about the diameter of a finger with a blocking balloon or cuff is inserted via the opening into the trachea and connected to a ventilator that applies cyclic positive pressure. This procedure makes sufficiently deep respiration possible, but prevents the patient from speaking.
In addition to home ventilation with a mask and invasive ventilation, there is also transtracheal administration of oxygen via thinner catheters. U.S. Pat. Nos. 5,181,509 or 5,279,288 disclose corresponding embodiments. In this manner, a highly dosed administration of oxygen is administered to the patient in a continuous stream with a permanently adjusted frequency. The flow rate of oxygen is regulated manually by a regulator. However, simulation of the natural breathing process of a patient is not achieved because the depth of breathing is not enhanced. Some common problems associated with these transtracheal catheters are irritations and traumas of the sensitive inner skin of the windpipe (tracheal mucosa). It is a common observation that the tip of the small catheter strikes against the inner wall of trachea as a consequence of the respiratory movement. In addition to this mechanical trauma, the surrounding tissue is dried out by the high flow oxygen stream.
Furthermore, so-called “Montgomery T-tubes” can be inserted into the trachea and a patient can obtain oxygen via a shank of the T-piece external to the patient. In needed, the patient can draw off secretions using a suction catheter and a vacuum pump. The patient can breathe freely and speak when the front shank is closed; however, normal artificial positive pressure ventilation is not possible via the Montgomery T-tube since the introduced air escapes upward into the oral cavity or the pharyngeal area. An additional limitation of the above-referenced therapies is the impaired mobility of the patient because of inadequate ventilation or because of the bulk of the apparatuses.
Jet ventilators are state of the art, but these devices are not synchronized with a patient's breathing. On the other hand, invasive ventilators with cuffed tubes are synchronized because there is a direct feedback of the pressure inside the inflated lung to the sensors inside the respirator. However, there are no respiratory systems that use feedback from sensors in the body to properly synchronize and control the ventilator.
Whether the breathing disorder is COPD/emphysema, fibrosis, sleep apnea, or otherwise, difficult breathing is a serious, often life-threatening problem. Therefore, there is an existing need for a respiratory system that provides a more efficient method for supporting the respiration of a patient that can be used to treat many disorders, are minimally invasive, mobile and taken along by the patient, and/or reliable in use. Moreover, there is a need for respiratory support systems that simulate the patient's spontaneous respiration without adversely affecting the patient's ability to speak. Additionally, there is a need for a respiratory support system capable of using pressure or flow signals from inside the body to properly synchronize and control a ventilator.